Cryogenic Microwave Impedance Microscope with Pulsed Laser Stimulation for Studying Phase Transitions
Abstract
This DURIP project aims to develop a cryogenic microwave impedance microscope (MIM) with pulsed white-light laser stimulation for the research of photo-induced phase transitions (PIPTs). Owing to the intricate interplay among disorders, electron-electron interactions, and competing orders, electronic inhomogeneity is ubiquitously observed in semiconductors, complex oxides and other functional materials. On the other hand, experimental techniques that combine optical excitation and intrinsic conductivity imaging are challenging. With substantial experience on low-temperature impedance microscopy, the PIÕs group will integrate the cryogenic MIM and pulsed white-light illumination to perform the following innovative investigations: (1) Nanoscale coexisting phases in chalcogenide glasses. The complex nature and rich phase diagrams of chalcogenide compounds make them an ideal playground in searching for novel photo-induced phases beyond the simple crystalline and amorphous states commonly used for phase-change applications. (2) Light-driven versus temperature-driven phase separation in transition metal oxides. The sizes, shapes, and evolutions of the coexisting phases during PIPTs will be compared with those in conventional thermodynamic processes. (3) Spatial distribution of photo-induced hidden states associated with charge-density waves. The formation and melting processes will shed some light on the dynamics of the resultant stable or meta-stable phases. The proposed program introduces a new tool for probing light-driven phenomena in novel quantum materials at the nanoscale, which is of fundamental importance for Army applications in sensing and data storage devices. The work will establish a new research direction and augment existing DoD programs at UT-Austin. Graduate and undergraduate students will be recruited and trained for their participation in this ARO funded project.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 15, 2018
- Source ID
- W911NF1710190
Entities
People
- Keji Lai
Organizations
- Army Contracting Command
- United States Army
- University of Texas at Austin